There’s something in the air in Aamjiwnaang First Nation. The community is located next to an industrial area of Sarnia, Ont., known to many as Chemical Valley. There are dozens of factories and refineries here, accounting for 40 per cent of Canada’s chemical industry — and an enormous amount of air pollution.

That pollution comes in many forms, but the levels of one chemical in particular caused Aamjiwnaang to declare a state of emergency last spring. Benzene is a byproduct of petroleum refining, used to make Styrofoam and other plastic materials. It’s also a volatile organic compound — a category of chemicals that evaporate easily into the air. Inhaling very high amounts can make you very sick, very quickly. And constantly breathing benzene-laden air, even in very small amounts, can do a lot of damage, too — notably by increasing your risk of leukemia and other cancers. 

Ontario’s Environment Ministry set emissions benchmarks much higher than those that triggered the state of emergency, which remains active to this day. A recent investigation by The Narwhal showed the province knew about the health risks this posed to the Aamjiwnaang community, and failed for years to take action that would meaningfully control benzene exposure. 

It wasn’t until after the state of emergency was declared that the ministry introduced stricter regulations aimed at controlling emissions from INEOS Styrolution, the chemical plant located across the street from Aamjiwnaang’s band office, and the primary source of benzene emissions in the area. 

Ontario’s Environment Ministry didn’t answer detailed questions related to these findings. INEOS Styrolution said it “consistently operated within the strict limits” set by the ministry. The company halted operations last spring and went on to decommission the facility, but said the closure was not related to the benzene spikes.

How much benzene in the air is too much? And what does that actually look like? Here’s a graphic, numerical look at the story of benzene pollution in Aamjiwnaang. Each represents concentrations of the chemical, averaged over different periods of time, and are expressed in micrograms per cubic metre of air. 

This series of graphics demonstrates the large discrepancy between the levels known to cause measurable health impacts, the levels that residents say caused serious symptoms of illness and the levels the Ontario government used to assess whether the company was doing enough to control its emissions.

Benzene levels, averaged over a single hour

191 micrograms per cubic metre, left: This was the maximum hourly reading recorded at an air monitor in Aamjiwnaang on April 25, 2024, the day the First Nation triggered a state of emergency. The community has recorded even higher hourly concentrations; in 2023, the maximum hourly level recorded was 372 micrograms per cubic metre. The First Nation now uses a benchmark of 27 micrograms per cubic metre to trigger the closure of some facilities.

580 micrograms per cubic metre, right: Ontario also gave this number to INEOS in 2019 as a benchmark to assess the risk of short-term health impacts. It’s based on standards from Texas that have been criticized as too lenient and allowing unacceptable increases in the risk of cancer. It is also several times higher than the levels in Aamjiwnaang when several people went to the hospital with headaches and nausea.

Benzene levels, averaged over a 24-hour period

2.3 micrograms per cubic metre, left: This is the level the Ontario government says could indicate a higher cancer risk with long-term exposure.

50 micrograms per cubic metre, centre: This was the average concentration level recorded by an air monitor in Aamjiwnaang on April 16, 2024. Around the same time, people in the community reported headaches and nausea, strong enough to send some to the hospital.

320 micrograms per cubic metre, right: This is the level the Ontario government said, in 2019, it would use to evaluate the risk of acute exposure from emissions from INEOS Styrolution, located across the street from Aamjiwnaang’s band office, playground and sports fields.

Benzene levels, averaged over a full year

0.45 micrograms per cubic metre, left: This is Ontario’s legal air quality limit for benzene. It is based on health studies that say this concentration, over a lifetime, presents a non-negligible increase in the risk of cancer. This isn’t enforced across the board; facilities that can’t meet it, including INEOS in Sarnia, are required to report emissions to the government and bring exposure down to a level that is “as low as reasonably achievable.”

4.5 micrograms per cubic metre, right: In 2019, the Ontario government told INEOS it should aim to gradually reduce its benzene emissions to this level to reduce the cancer risk to people nearby. It’s also the level established as a regulatory limit in June 2024. Annual recorded concentrations of benzene in Aamjiwnaang, measured at the band office monitoring station, were about 6.5 micrograms per cubic metre in 2019 and in 2023. That’s about ten times as much as industrial areas in Michigan and California, included for comparison in a 2024 health report.

— With files from Emma McIntosh

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Trouble in the Headwaters, a powerful 25-minute documentary by filmmaker Daniel J. Pierce, explores the root causes behind the devastating 2018 floods in Grand Forks, B.C. More than 100 families were displaced and millions of dollars were spent on flood infrastructure — yet floods continue to threaten the region. So what’s going on?

The film — which you can watch in full below! — follows Dr. Younes Alila, a professor of forest hydrology at the University of British Columbia, as he investigates the upstream impacts of clear-cut logging in the Kettle River watershed. With compelling field footage and scientific insight, The Narwhal presents a documentary that reveals how loss of forest cover has triggered a cycle of flooding, landslides and drought — transforming the landscape and endangering communities downstream.

“What is happening in the Kettle River basin is typical of what has been happening and will continue to happen for decades in other drainages across all of B.C.,” Alila told a crowd at the film’s global premiere in Victoria on June 12. Clear-cut logging in the Kettle basin, like elsewhere in the province, is extensive: two-thirds of the watershed has been harvested in the last 30 years.

“I think of the 2021 atmospheric river: the flooding of Merritt, the flooding of Princeton, the landslide on the Duffey highway,” Pierce added. “If you sort of pull on the thread and you look upstream, it’s the same picture in all of these places. The big Chilcotin landslide from last summer — if you look upstream across the whole Chilcotin plateau: dramatic forest cover loss. So, yeah, this is such a bigger story than we had time to get into in this film.”

Alila came to forest science in the 1990s as an outsider. From his experience in urban hydrology and as a professional engineer, he saw cracks in the way scientists have studied the impacts of clearcuts on floods.

Climate change is responsible for some of the increase in flooding. But decades of research by Alila and his peers suggests the role of industrial forestry is significant, and has long been underestimated and overlooked. He spent years investigating the problem with the existing methodologies and developing a new paradigm — one that actually accounts for how the cumulative effects of clearcutting are increasing the frequency of major flooding events in B.C.

His published findings, including a landmark 2009 paper, sparked heated debates in the pages of scientific journals. But Alila came to realize that convincing his peers was only part of the battle. After the 2021 atmospheric river that caused devastating floods in the Fraser Valley and elsewhere, he decided it was time to speak up — publicly.“I’m on a mission, and I’m advocating for what I think is the only defensible science that should guide management,” he said.

Alila sees hope in ongoing class-action lawsuits: people impacted by floods in Grand Forks, Chemainus and elsewhere in B.C. are suing governments and forestry companies, arguing that allowing overharvesting of trees contributed to the harm.

“I think we’re moving into an era of decades in B.C. where we’re going to see more and more of these legal actions against the forest industry and government,” Alila said.

As for Pierce, whose film was made possible with support from the Sitka Foundation and the Science Media Centre of Canada, he says he wants to see a massive investment in the health of forests across the country. “Right now, we’re spending untold billions of dollars, year after year, putting out wildfires and responding to floods and responding to these disasters — and the costs that are coming down the line are absolutely gargantuan,” he said.

If we put half that amount into restoring the ability of forests to reduce floods and mitigate wildfire risks, “not only would that pay dividends for generations to come, but we could put so many people to work in an effort like that,” Pierce said. “Workers need to see themselves in that story, and communities need to see themselves protected in that story.”

“Yes, it’s going to be a massive investment, but that investment will pay off, and it pales in comparison to what we’re going to be paying if we just keep doing the same thing that we’re doing now.”

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